Control knob



FIG. 1 is a perspective view of a control knob in accordance with the present design;

FIG. 2 is a front view thereof; and,

FIG. 3 is a perspective view of another embodiment of a control knob in accordance with the present design.

The views of the control knob that are not supported by the present disclosure are hereby disclaimed.

The broken line showing of the bottom of the control knob is included for the purpose of illustrating a portion of the control knob and forms no part of the claimed design. 

CLAIM The ornamental design for a control knob, as shown and described. 